My buddy NavyBrian and I have been doing a lot of quad stuff lately, and recently got bit by the FPV bug. Therefore we needed a way to hold our 450 frames up to fit cameras underneath; extension legs. So Brian asked his machinist buddy if he could make something; they guy (I can't recall his hame) has done a few RC related parts for Brian free in the past, including some custom threaded tube mount to firewall adapters for our favorite 56gm motors (ax2213n). Those beauties were free, but this time he charged Brian a little for his time & materials. It was well worth it as you can see from the pictures I took of the ones Brian gave me last Monday (I owe you big time Brian!).
I got too excited to get them on my quad ASAP, so I didn't measure or weigh anything. All I know about them now is there's 4 set screws to grab on each leg of the DJI 450 frame, and the hole in the bottom of the mount takes a 3/16" OD rod. I glued some aluminum tube in with Welder, and tapped the ends for the 10-24 plastic caps bumpers.
I think Brian has a few extra sets he was thinking of selling, and of course if it's worth his while, Brian's machinist buddy would be willing to produce them for us hobbyists. Let me know your thoughts.